redheadedleague

Ah. Cool:

"Let the first digit of your number be A, and the second be B. Then your original number is (10*A+B), the sum of the digits is A+B, and the subtraction gives

(10*A)+B-(A+B) = 9*A

which shows that the second digit doesn't matter, and the final result will always be a multiple of 9. All the multiples of 9 have the same symbol on the chart."

It's clever that htey're smart enough to change the chart when you repeat it, but if they were *really* clever, they'd change the order that the symbols appear in every time you reload.

But yeah, neat.